1. Field of the Invention
Embodiments of the present invention relate to a color filter using a surface plasmon, a liquid crystal display (LCD) device, and a method for fabricating the same, and more particularly, to a color filter using a surface plasmon and having a three-dimensional (3D) pattern structure provided with a transmissive pattern for selectively transmitting light of a specific wavelength, an LCD device, and a method for fabricating the same.
2. Discussion of the Related Art
As concerns about information displays and demands for portable information media increases, research and commercialization of flat panel displays (FPD) to replace the related art display apparatus, Cathode Ray Tubes (CRT), are actively ongoing. One of these flat panel displays, a Liquid Crystal Display (LCD) device serves to display an image by using optical anisotropy of a liquid crystal (LC). Owing to excellent resolution, color reproduction characteristic, and picture quality, the LCD device is being actively applied to notebooks, desk top monitors, etc.
The LCD device is largely comprised of a color filter substrate, an array substrate, and an LC layer interposed between the color filter substrate and the array substrate.
The LCD device is fabricated through a plural number of mask processes (i.e., photo lithography process). Accordingly, required is a method for reducing the number of mask processes for enhanced productivity.
Hereinafter, a structure of the related art LCD device will be explained in more detail with reference to FIG. 1.
FIG. 1 is a perspective view schematically showing a related art LCD. As shown in FIG. 1, the LCD device largely comprises a color filter substrate 5, an array substrate 10, and an LC layer 30 interposed between the color filter substrate 5 and the array substrate 10.
The color filter substrate 5 consists of a color filter (C) composed of a plurality of sub color filters 7 for implementing red, green and blue (RGB) colors, a black matrix 6 for dividing the sub color filters 7 from each other and shielding light passing through the LC layer 30, and a transparent common electrode 8 for applying a voltage to the LC layer 30.
The array substrate 10 consists of a plurality of gate lines 16 and data lines 17 arranged in horizontal and vertical directions to define a plurality of pixel regions (P), Thin Film Transistors (TFT) as switching devices formed at intersections between the gate lines 16 and the data lines 17, and pixel electrodes 18 formed in the pixel regions (P).
The color filter substrate 5 and the array substrate 10 facing each other are bonded to each other by a sealant formed on an outer periphery of an image display region, thereby constituting an LC panel. The color filter substrate 5 and the array substrate 10 are bonded to each other by alignment keys formed at the color filter substrate 5 or the array substrate 10.
In order to prevent or reduce light leakage due to an alignment error when bonding the two substrates to each other, a line width of the black matrix is set to be wide, thereby obtaining an alignment margin. This may reduce an aperture ratio of the LC panel.
The conventional color filter used in the LCD device implements colors by absorbing light of unnecessary colors by using pigments or dyes, and by selectively transmitting light of desired colors. This may allow only one of RGB colors, source from white incident light, to be transmitted to one sub-pixel. Accordingly, it is difficult to have a transmittance ratio of more than 30%. Due to this low transmittance ratio of the LC panel, power consumption by a backlight is increased.
FIG. 2 is a view schematically showing a transmittance ratio of the LC panel when applying a color filter using a conventional pigment dispersing method. Referring to FIG. 2, as light incident from a backlight has a decreased optical amount decreased while sequentially passing through a polarizer, a TFT array, an LC and a color filter, a transmittance ratio thereof is reduced to 5% or less.
In this instance, the polarizer, the TFT array and the color filter approximately have transmittance ratios of ˜40%, 45˜55% and ˜25%, respectively.
The conventional color filter is fabricated with complicated processes since it repeatedly undergoes color resist coating, exposure to light, development and hardening processes according to each color.
Furthermore, in order to fabricate the color filter on the color filter substrate, production lines for color filter processing have to be implemented separately from production lines for TFT processing. This may increase line installation costs.